We propose to acquire a combined atomic force and optical microscope that will be equally useful for dynamic biological sample and soft/wet material research (Bio-AFM). The BioScope Resolve-Bio AFM (Bruker, Inc.) head and AxioObserver Z1 epifluorescence microscope (Zeiss, Inc.) base we are requesting has a versatile, modular design that combines the sub-molecular resolution imaging and precision force measurements of AFM with a broad range of optical microscopy techniques for simultaneous, correlative AFM and optical microscopy. This is a high performance Bio-AFM consisting of the following components: 1) Bio-AFM head equipped with an extended z-range head, Petri dish holder and stage heater, CO2 control, active vibration control and acoustic enclosure. 2) Inverted epifluorescence optical microscope on which to mount the AFM head; provides automated, diffraction limited resolution, wide-field epifluorescence and brightfield /phase imaging capabilities with piezo z-drive, sCMOS camera, and splitting optics, needed for correlative biological imaging studies utilizing AFM. The Bio- AFM and its requested accessories will serve first the specific needs of the NIH funded research projects described in this proposal and then the anticipated needs of the greater Stanford University and surrounding research community. This instrument will enable innovative experiments that will allow high resolution force measurements and mapping over the surface of soft materials, cells and other biological material. These force measurements will be correlated with macromolecules, proteins and subcellular structures as cells sense and respond to mechanical cues and environmental changes via epifluorescence, brightfield and phase contrast optical imaging. These otherwise not possible combinations of imaging experiments will result in dramatic and rapid progress in important health-related research topics in a variety of disciplines and interdisciplinary areas including the molecular and biophysical mechanisms underlying sensation of mechanical stimuli, engineering organoid cultures for regenerative medicine research, analysis of stem cell derived cardiomyocyte contractility and modeling familial dilated cardiomyopathy, correlating proteins involved in cell division with force distribution in dividing microbes and the manipulatio of T cell signaling pathways to control immunologically-mediated diseases. Stanford researchers, students, and staff are well-qualified - and eager - to carry out the research described here, to use the Bio-AFM to further these and other research efforts, to develop and publish novel methodologies for Bio-AFM, and to maintain the instrument within a shared imaging facility that will enable additional research.